/*
 * SimpleCharStream.java - ScriptME
 * 
 * Copyright (c) 2009 Cesar Henriques <cesar at alttab.com.ar>.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Based on FESI Project
 * 
 * Contributors:
 * 	Jean-Marc Lugrin - initial API and implementation
 * 	Cesar Henriques <cesar at alttab.com.ar> - J2ME Porting and Extensions
 */
/*
 * 
 */
/* Generated By:JavaCC: Do not edit this line. SimpleCharStream.java Version 3.0 */
package org.scriptme.ecmascript.parser;

/**
 * An implementation of interface CharStream, where the stream is assumed to
 * contain only ASCII characters (without unicode processing).
 */

public class SimpleCharStream {

	/** The Constant staticFlag. */
	public static final boolean staticFlag = false;

	/** The bufsize. */
	int bufsize;

	/** The available. */
	int available;

	/** The token begin. */
	int tokenBegin;

	/** The bufpos. */
	public int bufpos = -1;

	/** The bufline. */
	protected int bufline[];

	/** The bufcolumn. */
	protected int bufcolumn[];

	/** The column. */
	protected int column = 0;

	/** The line. */
	protected int line = 1;

	/** The prev char is cr. */
	protected boolean prevCharIsCR = false;

	/** The prev char is lf. */
	protected boolean prevCharIsLF = false;

	/** The input stream. */
	protected java.io.Reader inputStream;

	/** The buffer. */
	protected char[] buffer;

	/** The max next char ind. */
	protected int maxNextCharInd = 0;

	/** The in buf. */
	protected int inBuf = 0;

	/**
	 * Expand buff.
	 * 
	 * @param wrapAround
	 *            the wrap around
	 */
	protected void ExpandBuff(boolean wrapAround) {
		char[] newbuffer = new char[bufsize + 2048];
		int newbufline[] = new int[bufsize + 2048];
		int newbufcolumn[] = new int[bufsize + 2048];

		try {
			if (wrapAround) {
				System.arraycopy(buffer, tokenBegin, newbuffer, 0, bufsize
						- tokenBegin);
				System.arraycopy(buffer, 0, newbuffer, bufsize - tokenBegin,
						bufpos);
				buffer = newbuffer;

				System.arraycopy(bufline, tokenBegin, newbufline, 0, bufsize
						- tokenBegin);
				System.arraycopy(bufline, 0, newbufline, bufsize - tokenBegin,
						bufpos);
				bufline = newbufline;

				System.arraycopy(bufcolumn, tokenBegin, newbufcolumn, 0,
						bufsize - tokenBegin);
				System.arraycopy(bufcolumn, 0, newbufcolumn, bufsize
						- tokenBegin, bufpos);
				bufcolumn = newbufcolumn;

				maxNextCharInd = (bufpos += (bufsize - tokenBegin));
			} else {
				System.arraycopy(buffer, tokenBegin, newbuffer, 0, bufsize
						- tokenBegin);
				buffer = newbuffer;

				System.arraycopy(bufline, tokenBegin, newbufline, 0, bufsize
						- tokenBegin);
				bufline = newbufline;

				System.arraycopy(bufcolumn, tokenBegin, newbufcolumn, 0,
						bufsize - tokenBegin);
				bufcolumn = newbufcolumn;

				maxNextCharInd = (bufpos -= tokenBegin);
			}
		} catch (Throwable t) {
			throw new Error(t.getMessage());
		}

		bufsize += 2048;
		available = bufsize;
		tokenBegin = 0;
	}

	/**
	 * Fill buff.
	 * 
	 * @throws IOException
	 *             Signals that an I/O exception has occurred.
	 */
	protected void FillBuff() throws java.io.IOException {
		if (maxNextCharInd == available) {
			if (available == bufsize) {
				if (tokenBegin > 2048) {
					bufpos = maxNextCharInd = 0;
					available = tokenBegin;
				} else if (tokenBegin < 0)
					bufpos = maxNextCharInd = 0;
				else
					ExpandBuff(false);
			} else if (available > tokenBegin)
				available = bufsize;
			else if ((tokenBegin - available) < 2048)
				ExpandBuff(true);
			else
				available = tokenBegin;
		}

		int i;
		try {
			if ((i = inputStream.read(buffer, maxNextCharInd, available
					- maxNextCharInd)) == -1) {
				inputStream.close();
				throw new java.io.IOException();
			} else
				maxNextCharInd += i;
			return;
		} catch (java.io.IOException e) {
			--bufpos;
			backup(0);
			if (tokenBegin == -1)
				tokenBegin = bufpos;
			throw e;
		}
	}

	/**
	 * Begin token.
	 * 
	 * @return the char
	 * 
	 * @throws IOException
	 *             Signals that an I/O exception has occurred.
	 */
	public char BeginToken() throws java.io.IOException {
		tokenBegin = -1;
		char c = readChar();
		tokenBegin = bufpos;

		return c;
	}

	/**
	 * Update line column.
	 * 
	 * @param c
	 *            the c
	 */
	protected void UpdateLineColumn(char c) {
		column++;

		if (prevCharIsLF) {
			prevCharIsLF = false;
			line += (column = 1);
		} else if (prevCharIsCR) {
			prevCharIsCR = false;
			if (c == '\n') {
				prevCharIsLF = true;
			} else
				line += (column = 1);
		}

		switch (c) {
		case '\r':
			prevCharIsCR = true;
			break;
		case '\n':
			prevCharIsLF = true;
			break;
		case '\t':
			column--;
			column += (8 - (column & 07));
			break;
		default:
			break;
		}

		bufline[bufpos] = line;
		bufcolumn[bufpos] = column;
	}

	/**
	 * Read char.
	 * 
	 * @return the char
	 * 
	 * @throws IOException
	 *             Signals that an I/O exception has occurred.
	 */
	public char readChar() throws java.io.IOException {
		if (inBuf > 0) {
			--inBuf;

			if (++bufpos == bufsize)
				bufpos = 0;

			return buffer[bufpos];
		}

		if (++bufpos >= maxNextCharInd)
			FillBuff();

		char c = buffer[bufpos];

		UpdateLineColumn(c);
		return (c);
	}

	/**
	 * Gets the column.
	 * 
	 * @return the column
	 * 
	 * @deprecated
	 * @see #getEndColumn
	 */

	public int getColumn() {
		return bufcolumn[bufpos];
	}

	/**
	 * Gets the line.
	 * 
	 * @return the line
	 * 
	 * @deprecated
	 * @see #getEndLine
	 */

	public int getLine() {
		return bufline[bufpos];
	}

	/**
	 * Gets the end column.
	 * 
	 * @return the end column
	 */
	public int getEndColumn() {
		return bufcolumn[bufpos];
	}

	/**
	 * Gets the end line.
	 * 
	 * @return the end line
	 */
	public int getEndLine() {
		return bufline[bufpos];
	}

	/**
	 * Gets the begin column.
	 * 
	 * @return the begin column
	 */
	public int getBeginColumn() {
		return bufcolumn[tokenBegin];
	}

	/**
	 * Gets the begin line.
	 * 
	 * @return the begin line
	 */
	public int getBeginLine() {
		return bufline[tokenBegin];
	}

	/**
	 * Backup.
	 * 
	 * @param amount
	 *            the amount
	 */
	public void backup(int amount) {

		inBuf += amount;
		if ((bufpos -= amount) < 0)
			bufpos += bufsize;
	}

	/**
	 * Instantiates a new simple char stream.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 * @param buffersize
	 *            the buffersize
	 */
	public SimpleCharStream(java.io.Reader dstream, int startline,
			int startcolumn, int buffersize) {
		inputStream = dstream;
		line = startline;
		column = startcolumn - 1;

		available = bufsize = buffersize;
		buffer = new char[buffersize];
		bufline = new int[buffersize];
		bufcolumn = new int[buffersize];
	}

	/**
	 * Instantiates a new simple char stream.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 */
	public SimpleCharStream(java.io.Reader dstream, int startline,
			int startcolumn) {
		this(dstream, startline, startcolumn, 4096);
	}

	/**
	 * Instantiates a new simple char stream.
	 * 
	 * @param dstream
	 *            the dstream
	 */
	public SimpleCharStream(java.io.Reader dstream) {
		this(dstream, 1, 1, 4096);
	}

	/**
	 * Re init.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 * @param buffersize
	 *            the buffersize
	 */
	public void ReInit(java.io.Reader dstream, int startline, int startcolumn,
			int buffersize) {
		inputStream = dstream;
		line = startline;
		column = startcolumn - 1;

		if (buffer == null || buffersize != buffer.length) {
			available = bufsize = buffersize;
			buffer = new char[buffersize];
			bufline = new int[buffersize];
			bufcolumn = new int[buffersize];
		}
		prevCharIsLF = prevCharIsCR = false;
		tokenBegin = inBuf = maxNextCharInd = 0;
		bufpos = -1;
	}

	/**
	 * Re init.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 */
	public void ReInit(java.io.Reader dstream, int startline, int startcolumn) {
		ReInit(dstream, startline, startcolumn, 4096);
	}

	/**
	 * Re init.
	 * 
	 * @param dstream
	 *            the dstream
	 */
	public void ReInit(java.io.Reader dstream) {
		ReInit(dstream, 1, 1, 4096);
	}

	/**
	 * Instantiates a new simple char stream.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 * @param buffersize
	 *            the buffersize
	 */
	public SimpleCharStream(java.io.InputStream dstream, int startline,
			int startcolumn, int buffersize) {
		this(new java.io.InputStreamReader(dstream), startline, startcolumn,
				4096);
	}

	/**
	 * Instantiates a new simple char stream.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 */
	public SimpleCharStream(java.io.InputStream dstream, int startline,
			int startcolumn) {
		this(dstream, startline, startcolumn, 4096);
	}

	/**
	 * Instantiates a new simple char stream.
	 * 
	 * @param dstream
	 *            the dstream
	 */
	public SimpleCharStream(java.io.InputStream dstream) {
		this(dstream, 1, 1, 4096);
	}

	/**
	 * Re init.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 * @param buffersize
	 *            the buffersize
	 */
	public void ReInit(java.io.InputStream dstream, int startline,
			int startcolumn, int buffersize) {
		ReInit(new java.io.InputStreamReader(dstream), startline, startcolumn,
				4096);
	}

	/**
	 * Re init.
	 * 
	 * @param dstream
	 *            the dstream
	 */
	public void ReInit(java.io.InputStream dstream) {
		ReInit(dstream, 1, 1, 4096);
	}

	/**
	 * Re init.
	 * 
	 * @param dstream
	 *            the dstream
	 * @param startline
	 *            the startline
	 * @param startcolumn
	 *            the startcolumn
	 */
	public void ReInit(java.io.InputStream dstream, int startline,
			int startcolumn) {
		ReInit(dstream, startline, startcolumn, 4096);
	}

	/**
	 * Gets the image.
	 * 
	 * @return the string
	 */
	public String GetImage() {
		if (bufpos >= tokenBegin)
			return new String(buffer, tokenBegin, bufpos - tokenBegin + 1);
		else
			return new String(buffer, tokenBegin, bufsize - tokenBegin)
					+ new String(buffer, 0, bufpos + 1);
	}

	/**
	 * Gets the suffix.
	 * 
	 * @param len
	 *            the len
	 * 
	 * @return the char[]
	 */
	public char[] GetSuffix(int len) {
		char[] ret = new char[len];

		if ((bufpos + 1) >= len)
			System.arraycopy(buffer, bufpos - len + 1, ret, 0, len);
		else {
			System.arraycopy(buffer, bufsize - (len - bufpos - 1), ret, 0, len
					- bufpos - 1);
			System.arraycopy(buffer, 0, ret, len - bufpos - 1, bufpos + 1);
		}

		return ret;
	}

	/**
	 * Done.
	 */
	public void Done() {
		buffer = null;
		bufline = null;
		bufcolumn = null;
	}

	/**
	 * Method to adjust line and column numbers for the start of a token.<BR>
	 * 
	 * @param newLine
	 *            the new line
	 * @param newCol
	 *            the new col
	 */
	public void adjustBeginLineColumn(int newLine, int newCol) {
		int start = tokenBegin;
		int len;

		if (bufpos >= tokenBegin) {
			len = bufpos - tokenBegin + inBuf + 1;
		} else {
			len = bufsize - tokenBegin + bufpos + 1 + inBuf;
		}

		int i = 0, j = 0, k = 0;
		int nextColDiff = 0, columnDiff = 0;

		while (i < len
				&& bufline[j = start % bufsize] == bufline[k = ++start
						% bufsize]) {
			bufline[j] = newLine;
			nextColDiff = columnDiff + bufcolumn[k] - bufcolumn[j];
			bufcolumn[j] = newCol + columnDiff;
			columnDiff = nextColDiff;
			i++;
		}

		if (i < len) {
			bufline[j] = newLine++;
			bufcolumn[j] = newCol + columnDiff;

			while (i++ < len) {
				if (bufline[j = start % bufsize] != bufline[++start % bufsize])
					bufline[j] = newLine++;
				else
					bufline[j] = newLine;
			}
		}

		line = bufline[j];
		column = bufcolumn[j];
	}
}
